Rebound wall and method

ABSTRACT

A low profile rebound wall for use in sports activity is provided. The wall presents a substantially planar plumbed outer surface having almost totally uniform ball impact response characteristics and being free of vibration when struck. The wall includes spacer shims secured to a receiving surface. The spacer shims may have varying thicknesses to accommodate variations in the planarity and verticality of the receiving surface. The wall panels are in contact with the spacer shims, and a pourable material which will become adhesive and cohesive is poured between the panels and the receiving surface.

United States Patent [191 ()mholt REBOUND WALL AND METHOD [76] Inventor: Ray E. Omholt. Powerlock Systems, Inc., Mid-Atlantic Park, 590 Grove Rd., Thorofare, NJ. 08086 [22] Filed: Mar. 8, 1973 [2]] Appl. No.: 339,496

[52] U.S. CL. 52/309; 52/404; 52/415; 52/508; 52/743; 52/746 [51] Int. Cl E04b 2/40 [58] Field of Search 52/508, 404, 309, 743, 52/385, 386, 393, 403, 391, 480, 415, 746, 741, 389, 390, 393, 506

[56] References Cited UNITED STATES PATENTS 2,107,240 1/1938 Eilertsen 52/753 W 2,764,888 10/1956 Olson 52/366 2,895,704 7/1959 Urbain 52/508 3,045,294 7/1962 Livezey.... 52/403 3,176,055 3/1965 Loos 161/161 3,270,475 9/1966 Kodaras... 52/480 3,362,120 l/l968 Warrenm, 52/366 3,405,493 10/1968 Omho1t..,.. 52/480 3,444,280 5/1969 Pu1aski..... 220/9 F 3,511,001 5/1970 Morgan 52/480 July 8,1975

FOREIGN PATENTS OR APPLICATIONS 646,878 11/1950 United Kingdom 52/366 1,142,217 2/1969 United Kingdom 52/393 OTHER PUBLICATIONS American Builder, March, 1962, p. 125.

Primary Examiner-John E. Murtagh Attorney, Agent, or Firm-Seidel, Gonda & Goldhammer 5 7 ABSTRACT A low profile rebound wall for use in sports activity is provided. The wall presents a substantially planar plumbed outer surface having almost totally uniform ball impact response characteristics and being free of vibration when struck. The wall includes spacer shims secured to a receiving surface. The spacer shims may have varying thicknesses to accommodate variations in the planarity and verticality of the receiving surface. The wall panels are in contact with the spacer shims, and a pourable material which will become adhesive and cohesive is poured between the panels and the receiving surface.

8 Claims, 2 Drawing Figures 1 REBOUND WALL AND METHOD The present invention relates to a rebound wall and a method of making the same and, more particularly, to a rebound wall construction and method which is of simple and inexpensive construction.

Rebound walls for use in sports activity have met with rapidly increasing popularity. The walls are used in the play of squash, handball, paddleball, variations of tennis, and the like.

The rebound wall should ideally provide uniformity of ball bounce, surface friction, and sound dampening to a ball striking the wall at any location on the wall. The rebound wall should be stable in the presence of changing atmospheric conditions, planar and accurately plumbed, and relatively quiet during play. Further, the wall should be resistant to cuts and dents which may be caused by racquet hits and should be resistant to localized spalling which may be caused by ball hits, a phenomena frequently observed with plaster walls. The wall should be resistant to condensation, especially at the 40 F. temperature at which championship squash is officially recommended to be played. The wall should have the lowest possible profile, especially when used to renovate an existing defective playing surface. This is important in order to maintain the integrity of the original dimensions of the playing court. Many design and playing factors which will be discussed hereinafter must be concurrently considered if a superior rebound wall construction is to be provided.

U.S. Pat. No. 3,405,493 discloses a wall construction which is adapted particularly for playing courts. The wall construction shown in U.S. Pat. No. 3,405,493 is excellent. It provides a wall construction having superior characteristics including uniformity of rebound, an intermediate profile, quietness of play, dimensional stability in the presence of changing atmospheric conditions, and the like. However, the components which comprise the wall construction in U.S. Pat. No. 3,405,493 are quite expensive. Further, a great deal of skilled labor is required to properly install the wall construction which very substantially adds to the expense thereof. In view of the rapidly increasing popularity of indoor athletic events requiring a rebound wall, it has become essential to develop a rebound wall which is inexpensive and easy to install and yet provides all the characteristics required for an excellent rebound wall.

The present invention is directed to a rebound wall construction and a method of making the same which provides a rebound wall having excellent player and design properties and yet which is inexpensive from both a material and labor standpoint. A plurality of spacer shims are secured to a receiving surface or to the rear faces of the rebound panels in any conventional manner. The receiving surface may be a cinderblock wall, plaster wall, concrete wall, wood wall or the like. The surface may be the inside face of an exterior wall, an interior partition wall or other substantially vertical continuous support wall and must have adequate strength and rigidity to provide support for the rebound wall.

The front face of the variable thickness spacer shims are positioned so that they lie in a substantially vertical and flat plane. The spacer shims may have a thickness varying from approximately one-eighth inch to a maximum thickness being determined by the lack of verticality and planarity of the receiving surface. When the rebound wall is secured to a relatively planar receiving surface each of the spacer shims utilized may be approximately one-eighth inch thick. Also, in this instance, the spacer shims can be secured to the rear faces of the panels rather than to the receiving surface. However, should the receiving surface be relatively nonplanar, spacer shims of varying thickness can be used to insure that the outer surfaces of the spacer shims will lie in a substantially vertical and flat plane.

Panels are preferably initially secured to the receiving surface by mechanical fastening means. The fastening means can include masonry anchors, nails, screws, staples, or similar fastening means. The fastening means preferably extend through both the panels and the spacer shims into the receiving surface. Alternatively, glue may be used to secure the panels to the spacer shims when the spacer shims have been previously secured to the receiving surface by either glue or mechanical fastening means.

The panels are normally one-half inch thick and are preferably made of relatively inexpensive paneling which may consist of a combination of dense surface composition material with a plywood core. Numerous panels meeting this description are commercially available. When mechanical fastening means are used to secure the panels against the spacer shims and to the receiving surface, the mechanical means may be intentionally overdriven below the face of the panel and the surface of the panel filled so as to provide an unblemished playing surface.

After the panels have been secured against the spacer shims, a pourable material which will become both adhesive and cohesive is introduced between the panels and the receiving surface. In the preferred form of the invention, a liquid urethane material is introduced which, after it cures to a rubber-like form, provides complete support for the panels and acts additionally as an adhesive to further prevent movement of the panels either with respect to the receiving surface or to each other. As the urethane cures and passes from a liquid to a solid form, there is substantially no change in volume which might otherwise tend to create voids behind the panels. An acceptable material is Versaturf 360, a trademarked two component cellular or noncellular filled urethane elastomer marketed by Powerlock Systems, Inc.

The cured urethane exerts a substantial permanent fixed adhesive force between the inner faces of the panels and the receiving surface. Other suitable materials can be used without departing from the present invention.

Adjacent panels may be provided with conventional tongue and groove interlocking means which provide additional strength at their edges and aid in preventing leakage of the poured material prior to solidification. Also, the tongue and groove edges can have glue applied thereto to insure the desired contact. Further, joints between adjacent panels can be staggered with respect to adjacent rows of panels. The urethane may be poured in stages as the panels are installed, or the whole wall may be poured or pumped full of urethane at one time.

The uppermost row of panels may be provided with holes or ports near their uppermost edges to permit the introduction by pouring or pumping of the pourable urethane behind the uppermost row in the event that a ceiling would interfere with normal pouring techniques. Generally, it is not essential that the very top of the wall have the urethane material therebehind since this portion of the wall receives little use. However, as stated, the material can be introduced under pressure to fill the void behind the entire wall including the up permost row of panels. The ports in the uppermost row of panels may then be plugged in any suitable conventional manner.

Prior to painting, the seams between adjoining panels can be sanded to insure removal of any projecting lips.

There are numerous design and player considerations which must be simultaneously solved if a wall is to be considered of tournament quality. The following factors are those which are most important to the construction and design of tournament quality rebound walls.

1. Availability of Materials: The panels utilized for this rebound wall are readily commercially available. Additionally, any one of a wide variety of panels would be acceptable although the preferred type is a panel consisting of a center core of plywood laminated with glue and with a durable dense resinous composition secured to both faces. The spacer shims utilized can be of any commercially available material. The anchors used to secure the shims and panels to the receiving surface can be of any of a wide variety of commercially available anchors. Depending upon the type of receiving surface, masonry anchors, nails, screws or the like may be used. The material to be poured between the panels and the receiving surface can be a commercially available urethane system or the like which is poured and allowed to cure. Should glue be used to bind the edges of the panels or to secure the shims to the receiving surface, or to secure the panels to the shims, many commercially available glues can be utilized. Two suitable glues are Weldwood Contact Cement and Weldwood Plastic Resin Glue as sold by United States Plywood Corporation.

2. Cost: it is believed that the system utilizes materials which reduce to an absolute minimum the cost of a tournament quality rebound wall. Further, since the method of installation is relatively simple and rapid, labor costs are kept at a minimum. While pourable urethane is a relatively expensive product, the amount of urethane used is not great since the space being filled normally varies between one-eighth inch and onequarter inch. The pourability of the urethane favors its use when a narrow space is being filled, and it is advantageous to use the narrowest space practical from a pouring viewpoint to save materials and to limit the outward force exerted by the poured liquid on the panels prior to setting up.

3. Profile Depth: In renovating existing playing courts it is important that the profile depth of the new wall surface be held to a minimum or the original court dimensions could be reduced to a degree rendering the court unsuitable for tournament play. Even with respect to new installations, a minimum profile depth permits the internal dimensions of a building to be held to a minimum thereby reducing building construction expense. In the preferred embodiment, the total profile depth of the rebound wall is five eights of an inch. The profile depth includes the one-eighth inch thick shim and the preferred k-inch thick panel spaced from the receiving wall by the spacer shim. Obviously, if the receiving wall is not substantially vertical, varying thickness shims will be required to provide a substantially vertical rebound wall. It is believed that the instant wall provides a minimal profile depth without sacrificing quality or playability.

4. Speed of Installation: With regard to renovating existing courts, minimizing down time of the court is very important to insure against lost revenue. With respect to new courts, rapid installation permits prompt usage of the court. Accordingly, it is important that the rebound wall be installed as rapidly as possible. in view of the minimum number of components comprising the rebound wall of the present invention and the uncomplicated method of installation the same, maximum speed of installation is obtained.

5. Quietness During Play: in view of the restricted confines of a playing court, it is important that ball impact sounds be as reduced as possible. The cured urethane substantially prevents or eliminates vibration in the face of a panel as a ball strikes the panel thus controlling noise resulting from vibration, or from the existence of hollow spaces behind the playing surface.

6. Waterproofing: The rebound wall is designed to be substantially waterproof and humidity proof to prevent warpage or dimensional changes in the rebound wall. The cured urethane will not permit water or dampness to penetrate from the receiving surface into the panels. Additionally, the backpour utilized in the preferred embodiment will not permit the formation of any condensation behind the panels, and its insulating properties substantially limit condensation which might otherwise form on the face of the panels.

7. Insulation: Squash is preferably played at approximately 40 F. Accordingly, it is possible for condensation to form on the rebound walls during play if they are colder than the temperature of the air in the court. The backpour behind the panels has an insulating value and helps to reduce the formation of condensation on the rebound wall. This is advantageous since moisture on a playing wall causes balls to skid" on impact, which negates the advantage of a skilled player who uses a controlled -spin shot.

8. Uniformity of Rebound: Since urethane or other suitable fill material completely and solidly fills the space between the rear face of the panels and the receiving surface, there are no voids behind the panels. This insures that the entire rebound wall is in bearing and not in span. Accordingly, there is an almost total uniformity of rebound imparted to a ball no matter which portion of the surface of the rebound wall is struck.

9. Planarity: Since the thickness of the spacer shims may be varied so that the outer surfaces of the shims lie in a substantially vertical plane, planarity of the playing surface is easily and rapidly achieved. A rebound wall which is planar and vertical contributes substantially to obtaining uniform rebound.

l0. Versatility: The rebound wall constructed in accordance with the present invention is suitable for either squash, handball, racquet ball or paddleball without modifying the wall design, a multi-usage benefit which results from not having to provide for surface openings in the bottom portions of walls to provide for ventilation behind the playing surface. The backpour eliminates any need for behind-the-wall ventilation. The wall constructed in accordance with the present invention is believed ideal for all wall rebound sports commonly played on an indoor court.

11. Flatness of Playing Surface: Joints exist only where the 4 X 8 foot panels meet. Sanding these few joints results in a wall which is almost totally smooth as opposed to walls made up of numerous small boards which must all be sanded very carefully to achieve smoothness. Also, sanding these few joints eliminates raised seams which could deflect balls which strike them or injure players who might run against them.

12. Maintenance: Almost no maintenance is required with respect to the rebound wall of the present invention. Since vibration is substantially eliminated, essentially no structural depreciation resulting from impacts and vibration is encountered. Surface cleaning of the rebound wall is greatly simplified in view of the smoothness of the wall.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a fragmentary perspective view of a rebound wall constructed in accordance with the present invention, parts being broken away to show details of construction; and

FIG. 2 is a section view taken along lines 2-2 of FIG. 1.

Referring now to the drawings in detail wherein like numerals indicate like elements throughout the two views, there is shown in FIGS. 1 and 2 a rebound wall construction generally indicated by referencenumeral 10. The rebound wall is adapted to be secured to a continuous receiving surface 12. The receiving surface 12 may be a cinderblock wall, plaster wall, concrete wall, wood wall, or the like. The surface 12 may be an exterior wall, an interior partition wall, or other substantially vertical support but must have adequate strength and rigidity to provide support for the rebound wall. The surface 12 need not be accurately plumbed.

A plurality of spacer shims 14 are adapted to be secured directly to the receiving surface 12. The spacer shims l4 may be secured to the receiving surface 12 in any desired manner. As discussed in greater detail hereinafter, the shims 14 may alternatively be secured to the rear faces of panels. The spacer shims 14 may be any shape although in the preferred embodiment they are generally square with each side being approximately 2 inches. The thickness of each shim may vary with the minimal thickness being approximately oneeighth inch.

The exact thickness of each spacer shim 1 4 may be varied so that the front face of all the shims lie in a substantially vertical plane. This will insure a plumbed planar surface for the outer surface of the rebound wall. In practice, unless a receiving surface is substantially out of plumb, the thickness of the shims will rarely exceed one-quarter inch. The shims may be composed of any suitable commercially available material and untempered Masonite is used in one preferred embodiment. As is well known to those of ordinary skill in the art. Masonite is a fiberboard product which is substantially incompressible. Variable thickness shims may be secured to the surface 12 by means of nails, screws, masonry anchors, glue or the like, the particular type of securing means being dependent upon the composition of the surface 12.

The shims 14 are secured to the receiving surface 12 at spaced intervals. In the preferred embodiment, the shims 14 are provided in substantially vertical rows spaced on 2 foot centers with the shims within a row being spaced on 2 foot centers. A greater or lesser distance between rows of shims and vertically aligned shims can be used without departing from the spirit or scope of the present invention. Further, the shims can be randomly spaced, if desired.

For purposes of illustration, four adjacent rows of panels 18, 20, 22 and 24 are shown and will be discussed. ln practice, the rebound wall will comprise a greater number of rows of panels, although the number of rows of panels utilized can be varied without departing from the spirit or scope of the present invention. As illustrated in FIG. 2, one of the panels in row 22 is provided with a tongue 26 while an adjacent panel is provided with a groove 28 to insure a tight interlocking engagement between the panels. Tongue and groove interlocking means can also be provided at the edges of adjacent rows of panels. The vertical joints between panels may be staggered with respect to adjacent rows of panels.

The rows of panels 18, 20, 22 and 24 are preferably secured to the receiving surface 12 through spacer shims 14 by any suitable conventional mechanical means. The fastening means may take the form of masonry anchors such as shown at 30, or the like. Since the shaft of the mechanical attaching means 30 will preferably be driven through the panel 22 and spacer shim 14 into the surface 12, the composition of the sur' face 12 will determine the exact type of fastening means to be used. Each of the fastening means need not necessarily pass through the shim.

The mechanical fastening means may be intentionally overdriven and the holes thus created in the face of the panels filled to provide a smooth planar surface for the rebound wall.

The panels in each row are preferably 4 X 8 feet and are preferably installed with the long dimension horizontal for ease of handling and back pouring. In the preferred embodiment, the panels will be approximately one half'inch thick although the thickness of the panels may be varied without departing from the spirit and scope of the present invention.

After the row of panels 18 has been secured to the surface 12, a pourable material 32 in substantially liquid form which will ultimately become adhesive and cohesive may be poured between the rear face of the panels 18 and the receiving surface 12. The material 32 is preferably a liquid urethane which, when cured, provides support for the panels and acts as an adhesive to secure the panels to the receiving surface 12. As the urethane cures, it has volumetric stability which negates the creation of voids.

The flowability of the urethane is important since the space between the rear face of the panels 18 and the receiving surface 12 is preferably maintained at a minimum. The minimum space is approximately one-eighth of an inch with the maximum space being generally on the order of less than one-half inch.

1n the preferred embodiment, it is preferred that the urethane be poured after each row of panels is constructed to insure that the lateral liquid pressure is held to a minimum when first poured to keep the number of mechanical fasteners required to a minimum.

The uppermost row of panels 24 may be provided with holes or ports 34 near their uppermost edges to permit the introduction of pourable urethane behind the uppermost row of panels. Generally, it is not essential that the uppermost portion of the wall have any pourable material therebehind since it receives little use. However, if desired, the material 32 can be introduced under pressure to fill the void between the entire wall including the uppermost portions of the last row of panels 24. The ports 34 may be plugged with suitable plugs 36 in any conventional manner.

Alternatively, the anchors 30 can be of a particular type permitting withdrawal of the anchors once the urethane material 32 has permanently cured. The adhesive and cohesive strength of the cured urethane obviates the need for the anchors. Holes left in the faces of panels can be filled.

in the preferred embodiment of the invention, the outer face of each of the panels is painted. Prior to painting, the seams between the panels can be sanded to insure planarity between each of the panels by removing any projecting lips.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

1 claim:

1. A method of constructing an upright rebound wall on a substantially continuous receiving surface including the steps of providing a plurality of abutting vertically disposed panels the outer surfaces of which can comprise the playing surface of the rebound wall, selecting relatively large panels to minimize seams in the rebound wall, securing a plurality of relatively thin and substantially incompressible spacer shims directly between the panels and the receiving surface so that the panels are spaced from the receiving surface by only the shims and so that a gap exists between the panels and the receiving surface, directly contacting the receiving surface with one face of the shims, directly contacting the rear face of the panels with the opposite face of the shims, providing securing means sufficient to hold the panels in fixed spaced relationship with respect to the receiving surface, attaching the shims directly to the receiving surface, selecting the thickness of the shims so that the outer surfaces of the shims lie in a substantially vertical plane directly against the rear face of the panels, locating the shims at spaced isolated locations on the receiving surface with the shims being discrete in all directions, introducing a pourable material which will become adhesive and cohesive into the gap between the panels and the receiving surface, causing the pourable material to completely flow into and fill the gap and to flow around the isolated and discrete spacer shims, permitting the pourable material to set and bond the panels to the receiving surface solidly to thereby provide a solid base support for the panels, whereby a quiet and solid rebound wall having uniformity of rebound is attained.

2. A method of constructing a rebound wall as set forth in claim 1 comprising the steps of providing adhesive on both the vertical joints between adjacent panels and horizontal joints between adjacent rows of panels, and providing shims of various thicknesses to accom- I l o inodate irregularlttes 1n the receiving surface.

3. A method of constructing an upright rebound wall as set forth in claim I comprising the steps of spacing the panels from the receiving surface a distance of approximately one-eighth to one-half inch, and providing a curable elastomeric material as the pourable adhesive and cohesive material.

4. A method of constructing an upright rebound wall as set forth in claim 1 including the step of removing the securing means after the pourable material has been permitted to set.

5. A rebound wall comprising an upright rebound surface comprised of a plurality of abutting vertically disposed panels supported on a substantially continuous receiving surface, a plurality of relatively thin and substantially incompressible spacer shims secured directly between said surfaces, one face of said shims being in contact with said receiving surface, the thickness of the shims being selected so that the other face of said shims lie in a substantially vertical plane, said shims being attached to said receiving surface at isolated spaced locations, said shims being discrete in all directions, said rebound surface being defined relationship with respect to the receiving surface, attaching the shims directly to the receiving surface, selecting the thickness of the shims so that the outer surfaces of the shims lie in a substantially vertical plane directly against the rear face of the panels, locating the shims at spaced isolated locations on the receiving surface with the shims being discrete in all directions, introducing a pourable material which will become adhesive and cohesive into the gap between the panels and the receiving surface, causing the pourable material to completely flow into and fill the gap and to flow around the isolated and discrete spacer shims, permitting the pourable material to set and bond the panels to the receiving surface solidly to thereby provide a solid base support for the panels, whereby a quiet and solid rebound wall having uniformity of rebound is attained.

6. A rebound wall as set forth in claim 5 wherein said adhesive and cohesive material is a two component filled urethane elastomer, said panels have tongue and groove interlocking means for increased strength at all joints between panels, and adhesive between said panels at all joints for insuring intimate contact between said panels at said joints.

7. A rebound wall as set forth in claim 5 wherein said shims are substantially vertically aligned in rows, said rows are spaced on approximately 2 foot centers, said shims being substantially vertically spaced on approximately 2 foot centers, said panels being of approximately one-half inch in thickness, and having a front face of approximately 4 X 8 feet.

8. A rebound wall as set forth in claim 5 wherein the thickness of said poured material is approximately oneeighth to one-half inch, and said connecting means are removed from said panels after said material has been introduced into the gap between said panels and said receiving surface.

* i l i 

1. A method of constructing an upright rebound wall on a substantially continuous receiving surface including the steps of providing a plurality of abutting vertically disposed panels the outer surfaces of which can comprise the playing surface of the rebound wall, selecting relatively large panels to minimize seams in the rebound wall, securing a plurality of relatively thin and substantially incompressible spacer shims directly betwEen the panels and the receiving surface so that the panels are spaced from the receiving surface by only the shims and so that a gap exists between the panels and the receiving surface, directly contacting the receiving surface with one face of the shims, directly contacting the rear face of the panels with the opposite face of the shims, providing securing means sufficient to hold the panels in fixed spaced relationship with respect to the receiving surface, attaching the shims directly to the receiving surface, selecting the thickness of the shims so that the outer surfaces of the shims lie in a substantially vertical plane directly against the rear face of the panels, locating the shims at spaced isolated locations on the receiving surface with the shims being discrete in all directions, introducing a pourable material which will become adhesive and cohesive into the gap between the panels and the receiving surface, causing the pourable material to completely flow into and fill the gap and to flow around the isolated and discrete spacer shims, permitting the pourable material to set and bond the panels to the receiving surface solidly to thereby provide a solid base support for the panels, whereby a quiet and solid rebound wall having uniformity of rebound is attained.
 2. A method of constructing a rebound wall as set forth in claim 1 comprising the steps of providing adhesive on both the vertical joints between adjacent panels and horizontal joints between adjacent rows of panels, and providing shims of various thicknesses to accommodate irregularities in the receiving surface.
 3. A method of constructing an upright rebound wall as set forth in claim 1 comprising the steps of spacing the panels from the receiving surface a distance of approximately one-eighth to one-half inch, and providing a curable elastomeric material as the pourable adhesive and cohesive material.
 4. A method of constructing an upright rebound wall as set forth in claim 1 including the step of removing the securing means after the pourable material has been permitted to set.
 5. A rebound wall comprising an upright rebound surface comprised of a plurality of abutting vertically disposed panels supported on a substantially continuous receiving surface, a plurality of relatively thin and substantially incompressible spacer shims secured directly between said surfaces, one face of said shims being in contact with said receiving surface, the thickness of the shims being selected so that the other face of said shims lie in a substantially vertical plane, said shims being attached to said receiving surface at isolated spaced locations, said shims being discrete in all directions, said rebound surface being defined relationship with respect to the receiving surface, attaching the shims directly to the receiving surface, selecting the thickness of the shims so that the outer surfaces of the shims lie in a substantially vertical plane directly against the rear face of the panels, locating the shims at spaced isolated locations on the receiving surface with the shims being discrete in all directions, introducing a pourable material which will become adhesive and cohesive into the gap between the panels and the receiving surface, causing the pourable material to completely flow into and fill the gap and to flow around the isolated and discrete spacer shims, permitting the pourable material to set and bond the panels to the receiving surface solidly to thereby provide a solid base support for the panels, whereby a quiet and solid rebound wall having uniformity of rebound is attained.
 6. A rebound wall as set forth in claim 5 wherein said adhesive and cohesive material is a two component filled urethane elastomer, said panels have tongue and groove interlocking means for increased strength at all joints between panels, and adhesive between said panels at all joints for insuring intimate contact between said panels at said joints.
 7. A rebound wall as set forth in claim 5 wherein saId shims are substantially vertically aligned in rows, said rows are spaced on approximately 2 foot centers, said shims being substantially vertically spaced on approximately 2 foot centers, said panels being of approximately one-half inch in thickness, and having a front face of approximately 4 X 8 feet.
 8. A rebound wall as set forth in claim 5 wherein the thickness of said poured material is approximately one-eighth to one-half inch, and said connecting means are removed from said panels after said material has been introduced into the gap between said panels and said receiving surface. 